Correlators or articulators for use with casts of a dental model to develop prosthetic dentures or denture elements have been used for a number of years. These articulators range from a very simple device affording only fixed pivotal movement between a pair of casts to highly sophisticated and mechanically complex devices which are capable of simulating the full range of occlusal and masticatory registration unique to any patient. The relatively simple devices are generally inadequate to provide sufficiently accurately registered prosthetic restoration to avoid extensive vists with a dentist to obtain adjustments thereof while the very complex devices are time consuming to operate and require extensive training to use properly. In either situation, the costs incurred to the patient are substantial. Moreover, none of the prior art articulators permit disengagement of the casts from registration with one another without extensive realignment upon reengagement. Thus, a technician is usually forced to perform his work while the casts are mounted on the articulator. Such an environment is difficult to work in with speed and accuracy.
Each of the following listed U.S. patents are directed to dental articulators which incorporate lockable ball and socket elements to afford pivotal movement and extensible members to afford translational movement: U.S. Pat. Nos. 175,046, 530,524, 537,812, 565,326, 981,430, 1,736,006, 1,841,728, 2,571,280, 2,600,899, 2,608,762, 2,621,407, 2,765,533, 4,169,314, 4,196,518 and Belgian Patent No. 572,850.
An articulator which provides structure to effect a simple hinged movement without provision of mechanical structure for defining translatory movement or multi-axis pivotal movement is disclosed in U.S. Pat. No. 2,430,177. Simulation of the full range of occlusal and masticatory registration is obtained by resiliently flexing the articulator. Such resiliency is afforded by the coil spring like configuration of a wire element defining each leg of two pairs of legs. For a well trained and experienced technician, the freedom of movement afforded by this articulator is sufficient to permit the formation and adjustments of most prosthetic dentures. Accurate use of the device is predicated upon the formation within each cast of a dental model elongated sockets for receiving, capturing and retaining each of the four wire legs. The casts usually vary in overall physical size, depending upon the size of the patient's teeth to be simulated and the size and configuration of the base formed. To employ the articulator described in this patent, uniformity of spacing between the pairs of sockets in each pair of casts is of paramount importance. The demands imposed by such uniform spacing during formation of the casts is time consuming and requires an experienced technician. No adjustment capability exists within the articulator itself to accommodate differences in spacing, as would be expected as the size of pairs of casts vary in proportion to the physical size of the patient's jaws and the usually uniquely sized bases therefor. Other U.S. Patents describing articulators include U.S. Pat. Nos. 824,096, 3,429,045 and 3,466,750.